Dynamic gaskets are typically formed of cured elastomeric materials have a desirable set of physical properties typical of the elastomeric state. These gaskets typically show a high tendency to return to their original sized and shape following removal of a deforming force, and they retain physical properties after repeated cycles of stretching, including strain levels up to 1000%. Based on these properties, the materials are generally useful for making dynamic seal such as seals and gaskets.
In today's automobile engines, the high temperatures of use have led to the development of a new generation of lubricants containing a high level of basic materials such as amines. Seals are often in contact with such fluids during use, and are subject to a wide variety of challenging environmental conditions, including exposure to high temperature, contact with corrosive chemicals, and high wear conditions during normal use. Accordingly, it is desirable to make seals from materials that combine elastomeric properties and stability or resistance to the environmental conditions.
To meet the demands of the new lubricant technology, seals using fluorocarbon elastomers have been developed that are highly resistant to the basic compounds found in the lubricating oils and greases. Specifically seals formed of cured elastomers based on copolymers of tetrafluoroethylene and propylene have met great commercial success. The additives necessary to achieve this resistance, however, often reduce mechanical properties of the seal.
It would be desirable to provide an elastomeric or rubber composition seal that would combine a high level of chemical resistance with improved material properties. It would further be desirable to provide methods for formulating chemically resistant rubbers having such advantageous properties.